@Masoud 10:55 Jan 10, 2015
"Clamp on" is a verb, which is being used here as a compound adjective describing the light bulb holders. You clamp the light bulb holders on something. It must be hyphenated when it's used like this: it should be "clamp-on light bulb holders", as Lesley has indicated. Many people nowadays omit hyphens in compound adjectives that precede the noun they refer to, but in this case the hyphen is really essential, and I think that if it were present in your text you would have found it easier to understand.
Another common example, very similar to this, is "clip-on": you can have clip-on sunglasses (that you clip onto ordinary glasses), or a clip-on tie (that you attach to your shirt with a clip rather than tying it round your neck), for example. |